• Install Google Play Music on Android
  • Install Google Music Manager on desktop
  • Open Music Manager on desktop
    • select the “Upload” tab
    • select “Automatically upload songs added to iTunes”

As of this writing you can upload up to 50.000 songs. Using the Play Music app on your Android you might want to keep the songs on the device instead of streaming them. Therefor click the download button on the album of song you want.